SET-LRP in biphasic mixtures of fluorinated alcohols with water

Abstract

Biphasic-binary mixtures of 2,2,2-trifluoroethanol (TFE) or 2,2,3,3-tetrafluoropropanol (TFP) with water were used as reaction media to synthesize well-defined poly(methyl acrylate) (PMA) with chain end functionality close to 100% by SET-LRP. Non-activated Cu(0) wire was used as a catalyst, taking advantage of the Cu(0)-activation property that these fluorinated alcohols possess. Biphasic-binary mixtures of water, containing a ligand and Cu(II)Br₂ either generated by disproportionation of Cu(I)Br or externally added, and an organic solvent, containing a monomer and a polymer, were studied. Two N-ligands were investigated: the classic tris(2-dimethylaminoethyl)amine (Me₆-TREN) and tris(2-aminoethyl)amine (TREN), as a more economically attractive alternative for technological purposes. The results reported here support the replacement of Me₆-TREN by TREN, taking into account the fact that the latter requires small loadings of an externally added Cu(II)Br₂ deactivator and a ligand in the water phase to mediate a living radical polymerization process. Both catalytic systems ensure efficient SET-LRP processes with first order kinetics to high conversion, linear dependence of experimental M_n on conversion, narrow molecular weight distribution, and near-quantitative chain end functionality.